1. Field of the Invention
The present invention relates to a method of manufacturing a coil block used in a motor such as a step motor, a coil block manufactured by the manufacturing method, and a motor including the coil block.
2. Description of the Related Art
As a coil manufacturing method of forming a coil portion by winding a wire such as an electric wire around a core shaft, for example, the following method is known as described in Japanese Patent Application Laid-Open No. 2003-133155. The method includes: a first step of cutting a wire to a predetermined length and bending both ends of the cut wire to form bends; and a second step of, using a wire chuck having a chuck body for locking the bends of the wire and a core shaft protruding from the apical surface of the chuck body, rotating the wire chuck to wind the wire on the outer periphery of the core shaft in the state in which the bends of the wire are locked by the chuck body.
In such a coil manufacturing method, a support surface for regulating the winding start part of the wire is formed at the apical portion of the chuck body of the wire chuck, so as to protrude in the axial direction of the core shaft in the form of a spiral sloping surface. Thus, with the coil manufacturing method, the wire chuck is rotated to wind the wire on the outer periphery of the core shaft one turn and, upon the next winding, the wire is wound while being displaced in the axial direction of the core shaft so as not to hamper the next winding.
In the case where such a coil manufacturing method is used in a method of manufacturing a coil block in a step motor, there is a gap between the wire at the start of the winding and the end surface of a board attachment portion.